User's Manual

Page 128 SITRANS LR560 (mA/HART) – INSTRUCTION MANUAL 7ML19985KB01
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D: Technical Reference
Measurement Response
Response Rate (2.4.1.) limits the maximum rate at which the display and output respond to
changes in the measurement. There are three preset options: slow, medium, and fast.
Once the real process fill/empty rate (m/s by default) is established, a response rate can
be selected that is slightly higher than the application rate. Response Rate automatically
adjusts the filters that affect the output response rate.
Damping
Damping Filter (2.2.3.) smooths out the response to a sudden change in level. This is an
exponential filter and the engineering unit is always in seconds.
In 5 time constants, the output rises exponentially: from 63.2% of the change in the first
time constant, to almost 100% of the change by the end of the 5th time constant.
Analog Output
The mA Output (current output) is proportional to material level in the range 4 to 20 mA.
0% and 100% are percentages of the full-scale reading (m, cm, mm, ft, in). Typically mA
output is set so that 4 mA equals 0% and 20 mA equals 100%.
While the device is in PROGRAM mode, the output remains active and continues to
respond to changes in the device.
SITRANS LR560 automatically returns to Measurement mode after a period of inactivity
in PROGRAM mode.
Note: Units are defined in Quick Start Wizard (1.1.) and are in meters by default.
Response Rate
(2.4.1.)
Fill Rate/Min (2.4.2.)/
Empty Rate/Min (2.4.3.)
Damping Filter
(2.2.3.)
Slow 0.1 m/min (0.32 ft/min) 10 s
* Medium 1.0 m/min (3.28 ft/min) 10 s
Fast 10.0 m/min (32.8 ft/min) 0 s
Level (m)
Time (s)
smoothed output
input (level)
Damping example
time constant = 2 seconds
input (level) change = 2 m